Lock



FIG. 1 is a front perspective view of a lock showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken line showing at the horizontally oriented rectangular region portions of the lock, on the circular keyway region, and the bottom central region in FIGS. 1-6 represents unclaimed environmental subject matter and forms no part of the claimed design. 

CLAIM The ornamental design for a lock, as shown and described. 